Ultrastructural analysis of the functional copulatory organ of the male rotifer,Asplanchna brightwelli

The male rotifer copulatory organ is composed of a urethral canal extending from the tip of the copulatory organ internally to a layer of microvilli. The microvilli project from two different cell types, referred to as the internal and peripheral microvillar cells according to their location. At this microvillar junction a second canal, the vas deferens, continues posteriorly and enters the sperm duct region of the testis. The channel of the vas deferens is formed from the inner wall of three separate cells; the cap, intermediate and basal cells. Peripheral to these cells and parallel to them for their entire length, cross sections of seven prostate gland cells can be observed. Anteriorly, these gland cells are connected to the basal end of the microvillar layer via a short neck region, through which glandular secretion occurs only during copulation. The mechanism of secretion appears to be a form of exocytosis whereby the secretory granule membrane fuses with the cell plasmalemma so that rupturing at the point of fusion will release the granule content into the neck region. The prostate gland cells contain an abundance of autophagic vacuoles while most of the other cells of the copulatory organ contain primary lysosomes and cytolosomes. These organelles may be associated with the aging process in rotifers, or, as in the case of the prostate gland-autophagic vacuoles, with a fast organelle turnover during secretion.     

Induction of T cell responses and recruitment of an inflammatory dendritic cell subset following tumor immunotherapy with Mycobacterium smegmatis

Mycobacteria and their cell wall components have been used with varying degrees of success to treat tumors, and Mycobacterium bovis BCG remains in use as a standard treatment for superficial bladder cancer. Mycobacterial immunotherapy is very effective in eliciting local immune responses against solid tumors when administered topically; however, its effectiveness in eliciting adaptive immune responses has been variable. Using a subcutaneous mouse thymoma model, we investigated whether immunotherapy with Mycobacterium smegmatis, a fast-growing mycobacterium of low pathogenicity, induces a systemic adaptive immune response. We found that M. smegmatis delivered adjacent to the tumor site elicited a systemic anti-tumor immune response that was primarily mediated by CD8⁺ T cells. Of note, we identified a CD11c⁺CD40^intCD11b^hiGr-1⁺ inflammatory DC population in the tumor-draining lymph nodes that was found only in mice treated with M. smegmatis. Our data suggest that, rather than rescuing the function of the DC already present in the tumor and/or tumor-draining lymph node, M. smegmatis treatment may promote anti-tumor immune responses by inducing the involvement of a new population of inflammatory cells with intact function.     

Differences and similarities among three acidic endopeptidases associated with human erythrocyte membranes molecular and functional studies

The three acidic proteinases (designated I, II and III, respectively) associated with human erythrocyte membranes were solubilized and purified to an electrophoretically homogeneous state by conventional procedures. Comparative analysis of chemical properties, including amino acid composition and fragmentation by cyanogen bromide cleavage, revealed significant differences among proteinases I, II and III. On the other hand, complete identity among the three proteolytic enzymes was observed on the basis of the peptide bonds specifically hydrolyzed in both glucagon- and phenylalanine-deprived oxidized B chain of insulin. In fact, each of the three proteinases produced splitting of the glucagon molecule between phenylalanine-22 and valine-23, while the susceptible bonds in the oxidized B chain of insulin proved to be those between leucine-15 and tyrosine-16 and between phenylalanine-25 and tyrosine-26, respectively.     

Role of oxidative stress in the pathophysiology of bipolar disorder

In this work, we review the studies of oxidative stress markers, showing association with the pathophysiology of bipolar disorder (BD). BD is a prevalent, chronic and highly disabling psychiatric disorder. Several hypotheses have been postulated to explain the exact neurochemical mechanisms underlying the pathophysiology of BD, including a role for monoamines, gamma-amino butyric acid (GABA), glutamate, and second messenger singling pathways. More recently, oxidative stress has been implicated in the pathogenesis of BD. Recent studies have reported increased products of lipid peroxidation and alterations of the major antioxidants enzymes in patients with BD. It has been widely demonstrated that the generation of reactive oxygen species (ROS) plays a critical role in the pathophysiology of several neuropsychiatric disorders, such BD.     

Pituitary responsiveness to gonadotrophin-releasing and thyrotrophin-releasing hormones in children receiving phenobarbitone.

The effect of long-term treatment with phenobarbitone on pituitary responsiveness to gonadotrophin-releasing hormone and thyrotrophin-releasing hormone was studied in 20 boys being treated with the drug to prevent febrile convulsions. Baseline concentrations of luteinising and follicle-stimulating hormones were reduced as well as the responses of these hormones to stimulation with gonadotrophin-releasing hormone. Baseline prolactin concentrations were raised in comparison with those in normal children. The response of prolactin to thyrotrophin-releasing hormone, however, was impaired only in the children who had been receiving the drug for a long time. Phenobarbitone had no effect on the secretion of growth hormone. Further studies should be carried out to ascertain how long these effects on pituitary function last after phenobarbitone is withdrawn and whether this interference with pituitary function modifies the child''s subsequent development.     

Effects of Mountain Ultra-Marathon Running on ROS Production and Oxidative Damage by Micro-Invasive Analytic Techniques

Purpose

Aiming to gain a detailed insight into the physiological mechanisms involved under extreme conditions, a group of experienced ultra-marathon runners, performing the mountain Tor des Géants® ultra-marathon: 330 km trail-run in Valle d’Aosta, 24000 m of positive and negative elevation changes, was monitored. ROS production rate, antioxidant capacity, oxidative damage and inflammation markers were assessed, adopting micro-invasive analytic techniques.

Methods

Forty-six male athletes (45.04±8.75 yr, 72.6±8.4 kg, 1.76±0.05 m) were tested. Capillary blood and urine were collected before (Pre-), in the middle (Middle-) and immediately after (Post-) Race. Samples were analyzed for: Reactive Oxygen Species (ROS) production by Electron Paramagnetic Resonance; Antioxidant Capacity by Electrochemistry; oxidative damage (8-hydroxy-2-deoxy Guanosine: 8-OH-dG; 8-isoprostane: 8-isoPGF2α) and nitric oxide metabolites by enzymatic assays; inflammatory biomarkers (plasma and urine interleukin-6: IL-6-P and IL-6-U) by enzyme-linked immunosorbent assays (ELISA); Creatinine and Neopterin by HPLC, hematologic (lactate, glucose and hematocrit) and urine parameters by standard analyses.

Results

Twenty-five athletes finished the race, while twenty-one dropped out of it. A significant increase (Post-Race vs Pre) of the ROS production rate (2.20±0.27 vs 1.65±0.22 μmol^.min^-1), oxidative damage biomarkers (8-OH-dG: 6.32±2.38 vs 4.16±1.25 ng^.mg^-1 Creatinine and 8-isoPGF2α: 1404.0±518.30 vs 822.51±448.91 pg^.mg^-1Creatinine), inflammatory state (IL-6-P: 66.42±36.92 vs 1.29±0.54 pg^.mL^-1 and IL-6-U: 1.33±0.56 vs 0.71±0.17 pg^.mL¹) and lactate production (+190%), associated with a decrease of both antioxidant capacity (-7%) and renal function (i.e. Creatinine level +76%) was found.

Conclusions

The used micro-invasive analytic methods allowed us to perform most of them before, during and immediately after the race directly in the field, by passing the need of storing and transporting samples for further analysis. Considered altogether the investigated variables showed up that exhaustive and prolonged exercise not only promotes the generation of ROS but also induces oxidative stress, transient renal impairment and inflammation.